Respiratory syncytial virus infection in adult and paediatric patients admitted to intensive care in Australia: A nation-wide comparison with COVID-19.

Respiratory syncytial virus (RSV) is a major cause of serious acute lower respiratory tract infection in infants and the elderly. The lack of a licensed RSV vaccine calls for the development of vaccines with other targets and vaccination strategies. Here, we construct a recombinant protein, designated P-KFD1, comprising RSV phosphoprotein (P) and the E.-coli-K12-strain-derived flagellin variant KFD1. Intranasal immunization with P-KFD1 inhibits RSV replication in the upper and lower respiratory tract and protects mice against lung disease without vaccine-enhanced disease (VED). The P-specific CD4+ Tcells provoked by P-KFD1 intranasal (i.n.) immunization either reside in or migrate to the respiratory tract and mediate protection against RSV infection. Single-cell RNA sequencing (scRNA-seq) and carboxyfluorescein succinimidyl ester (CFSE)-labeled cell transfer further characterize the Th1 and Th17 responses induced by P-KFD1. Finally, we find that anti-viral protection depends on either interferon-γ (IFN-γ) or interleukin-17A (IL-17A). Collectively, P-KFD1 is a promising safe and effective mucosal vaccine candidate for the prevention of RSV infection.

After the COVID-19 pandemic, there was a surge of pediatric respiratory syncytial virus (RSV) infections, but national data on hospitalization and intensive care unit use and advanced respiratory support modalities have not been reported. To analyze demographics, respiratory support modes, and clinical outcomes of children with RSV infections at tertiary pediatric hospitals from 2017 to 2023. This cross-sectional study evaluated children from 48 freestanding US children's hospitals registered in the Pediatric Health Information System (PHIS) database. Patients 5 years or younger with RSV from July 1, 2017, to June 30, 2023, were included. Each season was defined from July 1 to June 30. Prepandemic RSV seasons included 2017 to 2018, 2018 to 2019, and 2019 to 2020. The postpandemic season was delineated as 2022 to 2023. Hospital presentation with RSV infection. Data on emergency department presentations, hospital or intensive care unit admission and length of stay, demographics, respiratory support use, mortality, and cardiopulmonary resuscitation were analyzed. Postpandemic season data were compared with prepandemic seasonal averages. A total of 288 816 children aged 5 years or younger (median [IQR] age, 8.9 [3.3-21.5] months; 159 348 [55.2%] male) presented to 48 US children's hospitals with RSV from July 1, 2017, to June 30, 2023. Respiratory syncytial virus hospital presentations increased from 39 698 before the COVID-19 pandemic to 94 347 after the pandemic (P < .001), with 86.7% more hospitalizations than before the pandemic (50 619 vs 27 114; P < .001). In 2022 to 2023, children were older (median [IQR] age, 11.3 [4.1-26.6] months vs 6.8 [2.6-16.8] months; P < .001) and had fewer comorbidities (17.6% vs 21.8% of hospitalized patients; P < .001) than during prepandemic seasons. Advanced respiratory support use increased 70.1% in 2022 to 2023 (9094 vs 5340; P < .001), and children requiring high-flow nasal cannula (HFNC) or noninvasive ventilation (NIV) were older than during prepandemic seasons (median [IQR] age for HFNC, 6.9 [2.7-16.0] months vs 4.6 [2.0-11.7] months; for NIV, 6.0 [2.1-16.5] months vs 4.3 [1.9-11.9] months). Comorbid conditions were less frequent after the pandemic across all respiratory support modalities (HFNC, 14.9% vs 19.1%, NIV, 22.0% vs 28.5%, invasive mechanical ventilation, 30.5% vs 38.0%; P < .001). This cross-sectional study identified a postpandemic pediatric RSV surge that resulted in markedly increased hospital volumes and advanced respiratory support needs in older children with fewer comorbidities than prepandemic seasons. These clinical trends may inform novel vaccine allocation to reduce the overall burden during future RSV seasons.

Objective To summzarize the impacts of respiratory syncytial virus (RSV) infection in the early period(< 72 h) on the postoperative course after open-heart surgery in pediatric patients, and to discuss the expe-riences on therapeutic strategies. Method From March 2005 to March 2008, 39 patients diagnosed to be RSV in-fection confmned by RSV antigen test were prospectively enrolled into RSV-infeetion group. Anoth.er 39 patients were randomly 1 : 1 matched with age and same type of congenital heart disease (CHD) during the same period who also underwent open-heart surgery without RSV infection (nonRSV-infection group) as control group. The medical records of these patients were retrospectivdy reviewed. The duration of mechanical ventilation (MV), length of ICU stay and hospital stay were compared between the two groups with Paired Student's t test. Meanwhile Fisher' s exact test was used to compare the differences in noninvasive positive pressure ventilation, incidence rate of re-intubafion and severe postoperative complications between groups. Patients in both groups were further divided into subgroups aceonting to differences in age, cyanosis and pulmonary arterial pressure in order to identify the dif-ferent impacts of RSV infection in patients in different settings. Results All the patients were survived and dis-charged home. RSV infection significantly prolonged the duration of MV, ICU and hospital stay (all P < 0. 05).In addition, it significantly increased the incidence of pulmonary atelectasis (P < 0.05). In patients under 6 months old, RSV infection resulted in prolongation of MV, ICU and hospital stay (all P <0.05); furthermore, it significantly increased the incidence of complications of low cardiac output syndrome and bacteria co-infection (both P = 0.05). In patients over 24 months, RSV infection had no significant impacts in all the parameters which are compared between the two groups. In patients with cyanotic CHD, RSV infection significantly prolonged the duration of MV, ICU stay and hospital stay (all P < 0.05). In patients with cyanotic CHD, RSV infection significantly prolonged the duration of ICU stay and hospital stay (P <0.05). In patients with pulmonary hyper-tension, RSV infection significantly prolonged the duration of MV, ICU and hospital stay(all P <0.05), and in-creased the incidence rate of concomitant infection (P < 0.05). However, in patients without pulmonary hyper-tension, RSV infection only significantly increased the length of hospital stay (P < 0.05). Conclusions RSV in-fection in the early period after open-heart surgery in pediatric patients has significant adverse impacts on the post-operative course, especially in those patients under 6 months old, patients with pumonary hypertension or cyanotic CHD. Early diagnosis, and effective circulatory and respiratory support,alone with antivirus results in a satisfied outcome. Key words: Congenital heart defect; Respiratory syncytial virus; Complications; Pediatrics; Infection

Background Respiratory syncytial virus (RSV) significantly impacts not only children but also adults. However, knowledge of the severity and outcomes among adult RSV inpatients is still limited. Objectives To clarify the short- and long-term health threats associated with adult RSV infections. Methods This retrospective observational study included 56,980 adult inpatients aged 18 years and older due to RSV or influenza infection between April 2010 and March 2022. After inverse probability weighting adjustment, we used Poisson’s regression to estimate the risk of outcomes. Results The RSV group had a higher risk of requiring mechanical ventilation during hospitalization compared to the influenza group (9.7% vs. 7.0%; risk ratio (RR), 1.35; 95% confidence interval (CI), 1.08–1.67). In-hospital mortality was comparable between RSV and influenza groups (7.5% vs. 6.6%; RR, 1.05; 95% CI, 0.82–1.34). RSV group was associated with increased risk of readmission within 1 year after surviving discharge (34.0% vs. 28.9%; RR, 1.19; 95% CI, 1.07–1.32) and all-cause mortality within 1 year of admission (12.9% vs. 10.3%; RR, 1.17; 95% CI, 1.02–1.36). In the age-stratified analysis, the RSV group aged 60 years and older had a higher risk than the influenza group for in-hospital death, readmission and all-cause mortality within one year. Conclusions RSV infections demonstrated comparable or greater health threats than influenza infections not only during hospitalization but also in long-term outcomes. The findings underscore the threat of RSV in adults, the impact on healthcare systems and the need for continued development of public health counter measures against RSV.

Asthma and respiratory syncytial virus infection in infancy: is there a link?

Respiratory syncytial virus (RSV) infection is a common cause of hospital admission. The association between chronic obstructive pulmonary disease (COPD) exacerbation and RSV infection is not well studied. To analyze the hospitalizations of patients with COPD and RSV infection in Spain between 2018 and 2022. The data used were obtained from the Spanish Hospital Discharge Database. We selected subjects aged ≥40 years diagnosed with COPD, admitted to the hospital from 1 January 2018 to 31 December 2022. The COPD population that met the selection criteria was subdivided based on the presence of an ICD-10 code for RSV infection. To obtain comparable populations, for each subject with COPD and RSV infection, a subject without an RSV code was selected, with the COPD code in the same diagnostic position (1 to 20), as well as the same year of admission, sex, and age. Among subjects aged ≥40 years, 1,429,288 were identified as having COPD, of whom 5673 also had RSV infection. The number of hospitalizations with COPD and RSV infection increased during the study period. The proportion of RSV infection among patients admitted for COPD increased significantly over time, from 0.32% in 2018 to 0.65% in 2022, p < 0.001. In-hospital mortality (IHM) increased over time, but the differences were not significant (6.23% in 2018 vs. 6.79% in 2022). Patients with COPD and RSV infection had, compared with those without RSV infection, a higher use of mechanical ventilation, both invasive (3.44% vs. 1.34%, p < 0.001) and noninvasive (8.09% vs. 4.51%, p < 0.001) and a higher proportion of intensive care unit (ICU) admission (7.21% vs. 3.9%, p < 0.001). After multivariate adjustment, a significant increase in IHM was found from 2018 to 2022 in subjects with and without RSV infection. The presence of RSV infection was associated with a higher mortality (OR 1.22; 95% CI 1.01-1.46). The proportion of RSV infection among patients admitted for COPD increased significantly over time. Patients with COPD and RSV infection had, compared with those without RSV infection, a higher severity, a higher use of mechanical ventilation, and a higher proportion of ICU admission. The presence of RSV infection was associated with IHM. These results can help to identify patients at higher risk and make decisions to avoid the increased risk of hospitalization and mortality in this population.

Nuclear-localized human respiratory syncytial virus NS1 protein modulates host gene transcription.

Background Most children with respiratory syncytial virus (RSV) infection have a self-limiting course that can be managed with supportive care, and hospitalization is uncommon. The objectives of this study were to evaluate the epidemiology, outcomes, associated comorbidities, and temporal trends in the prevalence of infants one to 24 months of age who required hospitalization for RSV infection in the United States of America from 1997 to 2019. Methods In this retrospective cross-sectional study, we utilized the Kids' Inpatient Database (KID) to investigate the prevalence and outcomes of RSV bronchiolitis within a large cohort of discharged patients from 1997 to 2019. We included children one to 24 months of age admitted with a diagnosis of RSV bronchiolitis. Neonates were excluded from the analysis. A chi-square for linear trend was used to analyze trends in the prevalence of RSV bronchiolitis hospitalization, the presence of complex chronic conditions (CCC), congenital heart disease (CHD), the use of non-invasive and invasive mechanical ventilation (NIV and IMV), and hospital mortality. Results There were a total of 566,786 infants aged one to 24 months hospitalized with RSV infection out of a total of 9,309,597 discharges during the eight-year cohort, with a hospital prevalence of 60.9 per 1000 discharges and a hospital mortality rate of 0.09% (95% confidence interval (CI): 0.08%-0.1%). There was no trend in hospitalization rates of RSV infections per 100,000 U.S. population during the study period, with a decrease in hospital mortality trend. Children with RSV bronchiolitis were more likely to have government insurance and reside in zip codes with the lowest income quartile. There was a significant seasonal and regional variation in RSV-related hospitalizations. The presence of CCC was identified in 2.4% of the RSV group compared to 5.1% of non-RSV discharges (odds ratio (OR): 0.46, 95% CI: 0.45-0.47; p<0.001). The prevalence of RSV among all discharges has significantly increased over the study period, rising from 51.6 cases per 1000 discharges in 1997 to 180.1 cases per 1000 discharges in 2019 (p<0.001). The prevalence of CCC and CHD among RSV patients has also shown an upward trend, with CCC cases increasing from 1,411 in 1997 to 2,795 in 2019 and CHD cases rising from 1,795 to 3,622 during the same period. The use of invasive mechanical ventilation, non-invasive ventilation, and extracorporeal membrane oxygenation has consistently increased over time. Additionally, complications such as the need for cardiopulmonary resuscitation have demonstrated a similar increasing trend, although they have remained overall low. However, population-based hospitalization rates showed no significant trend. Conclusions The hospitalization rates at a population level in the United States for RSV infection in children aged one to 24 months remained steady from 1997 to 2019, while hospital mortality rates showed a declining trend. There is an increased proportion of comorbid conditions and increased resource utilization in children with RSV. These findings are important for monitoring the effectiveness of preventive strategies for severe RSV infections.

OBJECTIVE: To compare resource utilization and outcomes between cohorts of pediatric and adult intensive care unit (ICU) patients from a single institution. DESIGN: Prospective, observational cohort study. SETTING: A large, urban, tertiary care medical center. PATIENTS: A total of 780 patients consecutively admitted to the pediatric ICU, adult medical ICU, and adult surgical ICU. MEASUREMENTS AND MAIN RESULTS: ICU, hospital and 6-month survivals and hospital costs from index ICU admission. Predicted mortality by Pediatric Risk of Mortality III and Acute Physiology and Chronic Health Evaluation II. Health status at 6 months from index ICU admission. Pediatric patients had lower ICU (7.8% vs. 13.7%; p =.01), hospital (10.1% vs. 16.9%; p =.009), and 6-month (16.2% vs. 29.2%; p <.001) mortalities compared with adult patients. Adult patients had significantly lower probability of survival for 6 months from initial ICU admission compared with pediatric patients. The difference in survival was primarily accounted for by adult and pediatric medical patients. No differences could be observed between pediatric and adult ICU patients for mean hospital costs ($33,316 +/- $48,467 vs. $32,877 +/- $46,411; p =.92). Pediatric and adult patients incurred increasing costs with increasing risks of mortality. More than 50% of pediatric patients had a risk of mortality <0.5% compared with 1.2% of adult patients, but there was no difference in the mean use of ICU-specific interventions. CONCLUSIONS: Pediatric critical care patients have better short-term and longer-term survival compared with adult patients. The difference in survival is accounted for by the lower survival of adult medical patients. Despite the survival differences, pediatric and adult ICU patients incur similar hospital costs, and the proportions of patients who receive active ICU interventions are similar.

BACKGROUND Respiratory syncytial virus (RSV) infection is an important cause of hospitalization and death in young children. The majority of deaths (99%) occur in low- and lower-middle-income countries (LMICs). Vaccines against RSV infection are underway. To obtain access to RSV interventions, LMICs depend on support from Gavi, the Vaccine Alliance. To identify future vaccine target populations, information on children with severe RSV infection is required. However, there is a lack of individual patient-level clinical data on instances of life-threatening RSV infection in LMICs. The RSV GOLD III-ICU Network study aims to describe clinical, demographic and socioeconomic characteristics of children with life-threatening RSV infection in Gavi-eligible countries. METHODS The RSV GOLD-III-ICU Network study is an international, prospective, observational multicenter study and will be conducted in 10 Gavi-eligible countries at pediatric intensive care units and high-dependency units (PICUs/HDUs) during local viral respiratory seasons for 2 years. Children younger than 2 years of age with respiratory symptoms fulfilling the World Health Organization (WHO) extended severe acute respiratory infection (SARI) case definition will be tested for RSV using a molecular point-of-care (POC) diagnostic device. Patient characteristics will be collected through a questionnaire. Mortality rates of children admitted to the PICU and/or HDU will be calculated. DISCUSSION This multicenter descriptive study will provide a better understanding of the characteristics and mortality rates of children younger than 2 years with RSV infection admitted to the PICU/HDU in LMICs. These results will contribute to knowledge on global disease burden and awareness of RSV and will directly guide decision makers in their efforts to implement future RSV prevention strategies. TRIAL REGISTRATION NUMBER NL9519, May 27, 2021.

Respiratory Syncytial Virus (RSV) infection causes seasonal respiratory illness in both children and adults, with increasing recognition of its impact in older adults with chronic comorbidities. This study aimed to characterize adult patients hospitalized with RSV infection in Switzerland and identify comorbidities linked to poor outcomes. Adults hospitalized with RSV infection between May 2022 and April 2024 at a Swiss public teaching hospital were included in this retrospective observational study. To assess the association between comorbidities and patient outcomes, separate multivariable regression analyses for each comorbidity, adjusted for age and sex, were performed. The primary composite endpoint was 'severe course' (in-hospital death or intensive care unit (ICU) admission), secondary endpoints included in-hospital death, ICU admission, and length of stay. Among 136 included patients (mean age 78, 38% male), 98% had comorbidities, most commonly cardiovascular (75.7%), respiratory (51%), and chronic kidney disease (CKD) (36.7%). Further, 18.4% experienced a severe course. The ICU admission rate was 14.0%, in-hospital mortality 6.6%, and the median hospital stay of survivors was 6 days (IQR 4-10). CKD was significantly associated with severe course (OR 2.64, p = 0.045) and in-hospital mortality (OR 11.6, p = 0.025), while immunosuppression predicted ICU admission (OR 5.7, p = 0.018). Length of stay was not linked to any comorbidities. In this cohort of hospitalized adults, mainly elderly individuals with chronic comorbidities were tested positive for RSV. CKD and immunosuppression were associated with severe course. Prevention strategies, including RSV vaccination, should prioritize these high-risk populations.

ObjectiveTo investigate whether COVID-19 infection was associated with increased risk for incident respiratory syncytial virus (RSV) infections and associated diseases among young children that might have contributed to the 2022...

Evidence suggests palivizumab may be beneficial for respiratory syncytial virus (RSV) infection in pediatric patients, although it is only approved by the US Food and Drug Administration for RSV prophylaxis. The objective of this study is to compare outcomes among pediatric patients with RSV infection who received intravenous palivizumab and standard of care versus standard of care alone. This is a retrospective, single-center cohort study conducted between November 2003 and October 2013. Pediatric patients with active RSV infection treated with intravenous (IV) palivizumab after initiation of mechanical ventilation were matched 1:1 to a control selected from ventilated patients who received standard of care. The primary end point evaluated the duration of mechanical ventilation between groups. Secondary end points included hospital length of stay, intensive care unit length of stay, duration of respiratory support over baseline, time to RSV microbiologic cure, duration of antibiotic therapy, and in-hospital mortality. A total of 22 patients with a median age of 3 months were included in the study. Patients in the treatment group received a median of 2 doses of IV palivizumab, with a mean dose of 14.2 mg/kg. All patients received bronchodilators and corticosteroids, with the exception of 1 patient in the control group, and only 1 treatment group patient received IV ribavirin. Duration of mechanical ventilation was longer in the treatment group (18.9 ± 9.5 vs. 14.3 ± 9.3 days; p = 0.26). No statistically significant differences were observed between groups for any of the secondary end points. Pediatric patients who received IV palivizumab in addition to standard of care for treatment of RSV infection following initiation of mechanical ventilation experienced similar outcomes to those who received standard of care alone. Further studies are necessary to evaluate the potential benefit of IV palivizumab in addition to current standard of care.

Objective To analyze the clinical features of infants infected by respiratory syncytial virus (RSV) or human rhinovirus (HRV) in lower respiratory tract in Suzhou area based on the month age and the month of the year. Methods From January 2013 to December 2015, 2 206 nasopharyngeal aspirates specimens were collected from the infants with lower respiratory tract infection. Direct immunofluorescence assay was performed to test RSV.Reverse transcription-polymerase chain reaction(RT-PCR) method was used to test HRV.The medical history was collected and pulmonary function tests were performed in some infants who were infected with RSV and HRV. Results In 2 206 cases, total RSV positive rate was 19.90%(439/2 206 cases) and simple RSV infection positive was detected in 399 cases. Total HRV positive rate was 14.14%(312/2 206 cases), in which simple HRV infection positive was detected in 250 cases and the detection rate of RSV was significantly higher than that of HRV(χ2=25.88, P 1-2 month, >2-3 month and >3-4 months respectively.Up to the age of 4 months old, the detection rate decreased gradually, and with the increase of age and the detection rate in >7-8 month group was only 10.96%(16/146 cases). The detection rate of HRV was 0(0/12)and 9.40%(44/468 cases) in the age group of 28 d-1 month, >1-2 month, respectively. After 2 months age old, the detection rate fluctuation ranged from 13.22% to 16.67%.The incidence rate of severe RSV infection was 12.30%(54/439 cases) and the incidence rate of severe HRV infection was 5.13%(16/312 cases). Increased respiratory rate was more common in patients with severe RSV infection while severe HRV infection in infants were accompanied by multiple lobar involvement.After RSV infection, the incidence rate of pulmonary function damage was 89.03%(276/310 cases). After HRV infection, 89.27%(183/205 cases)of the infants suffered from pulmonary function damage. Both RSV and HRV infection might cause pulmonary function damage. Conclusions RSV and HRV are the major pathogens in infants of Suzhou areas. The incidence of RSV-induced wheezing is significantly higher than that of HRV. RSV is detected positive mainly in winter and early spring and the infants within 4-month old are susceptible population.HRV is detected positive mainly in June, July and September and the infants older than 2 months are susceptible population. The incidence of severe RSV infection is significantly higher than that of HRV. Severe RSV infection may cause increased respiratory rate and severe HRV infection mainly cause multiple lobar involvement. RSV and HRV infection may cause pulmonary function damage. Key words: Infants; Respiratory syncytial virus; Human rhinovirus

Respiratory syncytial virus (RSV) is the most significant cause of paediatric acute respiratory infection (ARI). RSV and other respiratory viruses are commonly co-detected with potentially pathogenic bacteria, such as Streptococcus pneumoniae, in the upper airways of young children. While these bacteria are known to be carried asymptomatically, they are also capable of opportunistic infections. Interactions between RSV and S. pneumoniae have been demonstrated in both clinical and molecular studies. However, the clinical significance of these interactions remains debated, and the effect of clinically relevant strain variation in both virus and bacteria on these interactions is also unknown. This work aimed to better understand the role of S. pneumoniae colonisation during RSV infections. To determine the effect of RSV and S. pneumoniae co-detection on disease severity during ARI, molecular pathogen screening of nasopharyngeal samples was conducted in a cohort of young children under the age of two years presenting with ARI at the emergency department of the Royal Brisbane Children’s Hospital, Australia. S. pneumoniae was co-detected in approximately 52% of RSV infections, and co-detection was associated with increased disease severity, suggesting that S. pneumoniae plays a pathogenic role in severe paediatric RSV infections. Having established a clinical role for S. pneumoniae during RSV infection, the dynamics of pneumococcal colonisation of the nasal cavity was investigated in the four weeks prior and subsequent to an RSV infection in a longitudinal birth cohort of Brisbane-based children. Approximately 33% of infants and young children with RSV infections were colonised by S. pneumoniae prior to the RSV detection, and strain characterisation of S. pneumoniae in the weeks immediately surrounding the viral infection suggested that any observed growth of S. pneumoniae during RSV infection arose from the pre-existing strain colonising the URT. In another 14% of RSV infections, S. pneumoniae was first detected during the virus infection, suggesting simultaneous acquisition of RSV and S. pneumoniae and possible co-transmission of the two pathogens. The results from the two paediatric cohorts suggested an interaction between RSV and S. pneumoniae that was advantageous to the bacteria. It was therefore hypothesised that the molecular mechanisms governing RSV and S. pneumoniae interactions might be pneumococcal strain-specific and stronger in strains frequently co-detected with RSV. Studies have shown that RSV can increase S. pneumoniae colonisation by enhancing pneumococcal adherence to airway epithelia, and virions can bind directly to the bacterium to form co-pathogen complexes. These interactions are in part mediated through the binding interactions between S. pneumoniae surface receptors and the RSV G surface glycoprotein. RSV G is highly variable, both antigenically and genetically, and is the main protein used to type RSV into subtypes A and B. The genetic variation of RSV G was characterised from nasopharyngeal samples of young children under the age of five years with respiratory symptoms collected from Pathology Queensland Central at the Royal Brisbane Women’s Hospital. The core genetic variation, through multilocus sequence typing, and molecular serotype of S. pneumoniae isolates from the same cohort was also determined. S. pneumoniae co-detection was more common with RSV-A compared to RSV-B; however, there were no clear associations between virus co-detection and bacteria strains. An in vitro binding assay was developed to specifically investigate pneumococcal strain variation in adherence to immortalised airway epithelial cells during RSV infection or after pre-binding with RSV virions. S. pneumoniae strains were isolated from the paediatric pathology cohort to investigate whether strains isolated from patients with RSV infections exhibited greater adherence to RSV infected epithelial cells. The results suggested that the effect of RSV on pneumococcal adherence to the epithelial cells differed between S. pneumoniae strains and isolates, although no significant association was identified between strains isolated from children with RSV infections and increased RSV-mediated adherence. This project has demonstrated a pathogenic role for S. pneumoniae in RSV infection of young children. The results suggest that one mechanism of this interaction may be mediated through binding interactions between the bacteria and RSV surface glycoproteins, potentially resulting in outgrowth of S. pneumoniae colonising the URT during virus infection or possible co-transmission of virus and bacteria. The results from the paediatric cohorts have suggested that the presence of both S. pneumoniae and RSV should be considered during the diagnosis and treatment of paediatric ARI, while the molecular investigations have given insight into the strain-specific variation of interactions between the two pathogens, and provided a panel of characterised, clinically relevant S. pneumoniae isolates for use in further studies.